1. Field of the Invention
The present invention relates to a method increasing feed intake, feed efficiency, daily gain, and carcass grade in ruminants by combining a rumen-protected choline compound with ration in an amount proportional to the concentration of added fat in the ration.
2. Description of the Prior Art
Choline is an essential nutrient for ruminants. Normally, choline is provided in adequate quantities as a result of synthesis by ruminal microflora in cattle-feeding programs using primarily forage-based diets. Protozoa appear to be the primary species involved in synthesis of choline. Consequently, diets that result in ruminal conditions which compromise growth and proliferation of protozoa may result in inadequate choline supply to the animal. High-concentrate diets frequently produce ruminal pH in the range of 5.5 to 5.8, which is less than optimal for proliferation of protozoa. Inclusion of fat in the diet may further reduce protozoal populations. This may be the consequence of lower ruminal pH that occurs with fat feeding, or may be due to some direct effect of fat on the protozoa. In any case, diets that induce low protozoa populations may benefit from addition of choline to the diet. Previous research has suggested that choline chloride is extensively degraded in the rumen.
Although "traditional" dogma would suggest that choline is not required for ruminants, several researcher have challenged this notion and examined the effect of choline supplementation to cattle (Rumsey, "Effect of Choline in All-Concentrate Diets of Feedlot Steers and on Ruminal Acidosis" Canadian Journal of Animal Science 65:135, 1985). Harris, et al. "Effect of Choline in a High-Roughage Steer Fattening Ration" Journal of Animal Science, 25:248, (1966) examined the affect of feeding 5.53 g of unprotected choline per head per day to finishing cattle receiving a high roughage finishing diet containing no additional fat. No significant difference were detected in feed gains, feed efficiencies, carcass grades, fat thickness, rib-eye area, and yield grade, although there was a slight increase in marbling for cattle consuming choline containing diets.
Rumsey et al., "Sulfur and Choline in All Concentrate Beef Finishing Diets" Journal of Animal Sciences, 41:416, 1975, fed unprotected choline to finishing cattle receiving a high concentration of grains (75.4% corn, 15% wheat) and observed improvements in feed efficiency and gain when choline was supplemented at 750 ppm. Wise et al., "Effect of Various Levels of Choline on Performance and Carcass Characteristics of Finishing Steers Fed an All-Concentrate Ration" North Carolina Agric. Exp. Sta AnS re. 139, Animal Health Ser. 10:22 (1966).
Rumsey, 1985, fed finishing feedlot cattle diets containing 0, 750, 1500, and 3000 ppm of additional unprotected choline and observed a moderate improvement in feed efficiency of cattle fed 750 ppm., but detriment effects when fed 1500 or 3000 ppm. The diet did not contain additional fat. Rumsey concluded that, "choline supplementation of all-concentrate diets fed to finishing beef steers does not measurably improve feedlot performance and carcass merit or consistently affect Rumania fermentation." Rumsey's data does suggest that choline may affect lipid metabolism similar to that of humans by increasing the ability of the liver to synthesize and enable transport of lipid to tissues.
It is known that pure choline chloride fed to ruminants is broken down in the rumen and is an ineffective treatment. It was then discovered that encapsulated choline could be used to enable the choline chloride to pass through the rumen without breaking down thus allowing absorption in the gut. For example, encapsulated choline has been added to ration for increasing the milk production in dairy cows, as described in U.S. Pat. No. 5,496,571.
Although other uses for rumen-protected choline have been explored, choline has not been successfullly employed as an agent to increase carcass grade, daily gain, feed intake, feed efficiency and/or degree of fattening in ruminants. It would therefore be desirable to provide a method of treatment of ruminants to increase carcass grade, daily gain, feed intake, feed efficiency and/or degree of fattening.